IPv4, IPv6 and CG-NAT: explained

Published: 29th April 2022 Updated: 23rd July 2025

In our digital-first world, everyone accesses the internet using a unique IP address in order to surf the web. For the last 40 years, internet users have been using IPv4 addresses, and these come with a number of limitations.

If you’re researching static IP, you may wish to learn more about IPv4 and its successor, IPv6, as well as understanding CG-NAT. Our expert team are here to answer all of your static IP–related questions.

what is IPv4?

IPv4 is the fourth version of the Internet Protocol and has been in place since 1983. It has been providing us with IP addresses for over 40 years and routes most of today’s internet traffic, however the global IPv4 address supply has been exhausted.

IPv4 consists of a 32-bit numerical address which limits the world to 4.3 billion IPv4 addresses. Whilst this sounds huge, if you consider the digital revolution that has taken place since 1983 and how many devices you own that connect to the internet, each needing access to an IP address, this once huge supply of IPv4 addresses has depleted quickly.

what is IPv6?

IPv6 is the next generation of the Internet Protocol.

IPv6 functions similarly to IPv4 but has a 128-bit IP address that also includes letters, meaning we won’t run out of them in the future. Fun fact: there are more IPv6 addresses than all the observable stars in the universe!

IPv6 has a better response time, efficient packet processing and improved security; future-proofing IP addressing for decades to come.

It’s worth noting that IPv6 has not yet been adopted by all devices and technologies. This means if you only have an IPv4 address, some websites and newer devices can’t be accessed or used.

You can see the gradual adoption of IPv6 that is being tracked by Google in the image below, or view the most up-to-date tracking for IPv6 adoption.

As standard, toob’s router operates with both IPv4 and IPv6 due to a number of older devices and websites not supporting IPv6. For example, if you’re into gaming and have an older console such as the original Xbox, this won’t ever be IPv6 compatible.

am I using IPv4 or IPv6?

It’s easy to find out if your network is running on IPv4 or IPv6, with a quick internet search there are tools that can quickly tell you. Another option is to check your broadband router settings to see if IPv6 is enabled, if it’s not you’ll be running on an IPv4 address.

what is CG-NAT? and what does it have to do with IPv4 and IPv6?

As we have a limited number of IPv4 addresses available, we can use something called CG-NAT – also known as ‘Carrier Grade NAT’ – or ‘Carrier Grade Network Address Translation’ to maintain our IPv4 network as IPv6 adoption grows.

CG-NAT is designed to share public IP addresses among broadband customers.

It future-proofs the use of IPv4 by sharing out a public IPv4 address to a number of houses rather than each house having a single IPv4 address – helping with the aforementioned global shortage of IPv4 addresses.

Although CG-NAT doesn’t resolve IPv4 address exhaustion, it is a necessary interim solution whilst the world transitions to IPv6.

At toob, your IPv4 address is part of CG-NAT by default, on all our home broadband products. You can add a static IPv4 which isn’t part of CG-NAT, of if you’re a business broadband customer this is included as standard.

what are public IPv4 addresses?

Public IP addresses are needed to access services such as hosted websites, gaming servers or anything requiring remote access to your home network.

These are directly accessible from the internet without the need to go through a translation service, such as CG-NAT.

what are local or “private” IPv4 addresses?

A local, or private, address is assigned to devices on your local area network (e.g. any device connecting to your toob router). These addresses are not accessible from the internet.

Every device has an IPv4 address, some devices – like your home router – may be assigned a public IPv4 address, while others might have a local or “private” IP address. The concept of private IP addresses was created in the 1990s to address IPv4 exhaustion, and a few IPv4 address ranges were reserved for this purpose. The difference is local IP addresses are not routable on the internet and are instead only local to your home network. The toob router will then do a network address translation – or NAT – to translate communication from said private IP address into the router’s assigned IP address so that it is able to communicate with the internet. This is true for both our CG-NAT and static IP customers.

For example, the toob router will allocate your TV or gaming device with a private IP address from the following private address range: “192.168.X.X”. All devices connected to the toob router will be allocated addresses from this same IP address range.

what are CG-NAT IPv4 addresses?

CG-NAT IPv4 addresses are allocated to toob routers in place of a public IP address. These are private IP addresses which connect to our CG-NAT systems. Internet traffic is sent from your toob router to the CG-NAT devices in our network which then performs a network address translation (NAT) from the private address to a shared public address which can access the internet.

Before local IP addressing was invented, every single device on the internet was allocated with its own dedicated public IP address.

If you’re a toob customer and have more questions about adding a static IP to your broadband, just contact our friendly customer services team on 023 9300 9300 who will be more than happy to help.

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